Fast cut-out pneumatic switch

ABSTRACT

Fast cut-out pneumatic switch using the action of a pressurized gas flowing through a valve surrounding the contact, to accelerate the opening of the latter, characterized in that the beginning of the opening operation of the contact and of the valve is effected by electrodynamic means controlled by an emission of current.

[ June 17, 1975 4/1966 Francemm......,....,...... 200/148 BV ABSTRACT 2Claims, 6 Drawing Figures 3.522.400 7/1970Golota.......i..,,.............v

FOREIGN PATENTS OR APPLICATIONS Primary Examiner-Robert S. MaconAttorney, Agent, or FirmSughrue, Rothwell, Mion, Zinn & Macpeak Fastcut-out pneumatic switch using the action of a pressurized gas flowingthrough a valve surrounding the contact, to accelerate the opening ofthe latter, characterized in that the beginning of the opening operationof the contact and of the valve is effected by electrodynamic meanscontrolled by an emission of current.

Inventors: Edmond Thuries, Pusignan;

Francois Joly, Lyon, both of France Assignee: Delle-Alsthom,Villeubanne, France Filed: Dec. 20, 1972 Appl. No.: 316,783

Foreign Application Priority Data Dec 21, 1971 200/148 BV; 200/148 RInt. C1.H01h 33/42 200/148 BU, 148 R References Cited UNITED STATESPATENTS 4/1969 Frowein.......,.,............. 200/148 BV United StatesPatent Thuries et al.

[ 1 FAST CUT-OUT PNEUMATIC SWITCH [58] Field 01'Search.................,.

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SHEET WW? .p 0 f W/ 0000000 00 v x v x F PATENTEDJUN 17 ms FAST CUT-OUTPNEUMATIC SWITCH BACKGROUND OF THE INVENTION 1. Field of the InventionThe invention concerns pneumatic switches intended to be opened within avery short time, for example in order to cancel defects in an electriccircuit very rapidly.

2. Description of the Prior Art It is already known that it is possibleto speed up the movement for the opening of a contact of a pneumaticswitch by fitting round that contact a valve arranged inside a cut-outchamber forming a high-pressure compressed gas tank, and by making thecontact zone communicate with a low-pressure enclosure, so that, whenthe contact and the valve open, an acceleration of the opening of thecontact is caused by the action of the compressed gas flowing from thehigh-pressure tank towards the low-pressure tank.

SUMMARY OF THE INVENTION The present invention is intended to provide apneumatic switch of simple construction which opens very fast, combiningthe beginning of opening by electrodynamic means with an acceleratedcontinuance of the opening movement under the effect of a compressedgas.

Its object is, more particularly, a pneumatic switch comprising acut-out chamber containing a compressed gas and, in that chamber, a setof contacts whose moving contact is installed 'on a moving rod crossingthrough a wall of the said chamber. The switch is characterized in thatthe said moving rod is hollow at least throughout the whole of itslength entering the said chamber, the inside of that rod communicating,through an opening in the portion of the rod outside the said chamber,with a low-pressure medium, and has, installed round the moving contact,the body ofa valve which, when the switch is in the closed position, isclosed and separates the inside of the said rod from the compressed gascontained in the said chamber. Electro-dynamic means, placed on theoutside of the said chamber, cause, when they receive a currentemission, the beginning of the opening movement of the said moving rod,and, subsequently, the opening of the said valve, this causing theaccelerated continuance of the opening movement of the said moving rodunder the action of the compressed gas contained in the said chamber.

These electrodynamic means may, to great advantage, be constituted bytwo coils exerting, between them, a repulsion effort at the instant ofthe said current emission: a fixed coil through which the said currentemission flows and a short-circuited coil fast with a moving part of themain contact and of the said valve.

Other characteristics and advantages of the invention will becomeapparent from the description of examples of implementing which will begiven with reference to the accompanying diagrammatic figures.

BRIEF DESCRIPTION OF THE DRAWINGS These figures are cross-sectionalviews in the axis of the cut-out chamber of a pneumatic switch, withlike numerals covering like components.

FIG. I is a partial, sectional view of a cut-out chamber with doubleaxial blowing means and a contact at the end.

FIG. 2 concerns a variant of FIG. 1 in which the end contact is replacedby a finger type contact.

FIG. 3 is another variant of FIG. I.

FIG. 4 shows a cut-out chamber in which the contact opens by the actionof two moving parts.

FIG. 5 shows a variant of the fluid-tight sealing system of a cut-outchamber of the type shown in FIG. 1.

FIG. 6 shows a cut-out chamber having a single axial blowing means.

DESCRIPTION OF THE PREFERRED EMBODIMENT In all these embodiments, theswitch comprises a cutout chamber consisting of an annular tank 1 filledwith a high-pressure gas and, on one side of that cut-out chamber, or onboth sides of the latter, a low-pressure tank or tanks 2 and 3.

Fluid-tight sealing between the tanks I and 2 is insured by a slidingseal 4. A valve 5, arranged in the tank 1, forms a seal between a fixedpart 6 and a moving part 7 sliding in the seal 4.

The casing 8 of the tank I is at least partly insulating. The passing ofthe electric current through the tank I is insured by a contact 9between a moving contact 10 fast with the part 7 and another contactwhich, in the example in FIG. I, is a semi-moving contact 11 at the end,on which the effort of a spring 12 is exerted.

The original opening pulse of the contact 9 is obtained by means of afixed coil 13, exerting a repulsion effort on the short-circuited coilI4, fast with the moving part 7 by means of an insulating rod I5.

In the example shown in FIG. I, a current emission in the coil moves thecontact I0 and the moving part 7 which respectively press against thecontact 11 and the seat of the fixed part 6 by a few millimeters. Thehigh-pressure of the tank 1 then suddenly exerts an effort on thesection of the mobile contact 10 and accelerates the movement of thelatter. The are which was set up between the contacts 10 and II isextinguished by the axial double blowing means, going from the tank 1towards the tanks 2 and 3 respectively, on the one hand, across thecontact 10, a tube 16 formed in the moving part and an orifice l7, andon the other hand, across the contact 11 and a tube 18 crossing thefixed part 6. The compressed air contained in the tanks 2 and 3 releasedinto the atmosphere, slowly and with a rela tively slight noise by meansoforifices 19 and 20 having small dimensions. These orifices may bereplaced by valves having a small cross-section connected with thecontrol means and insuring draining during a contact closing operation.Such valves are ofa known type and have not been shown.

In the opening position, immediately after the cutting out, the voltagebetween contacts is maintained by the air at the average pressureresulting from the balance of pressures after the high-pressure tank hasbeen relieved by the low-pressure tanks. On the outside, the voltage ismaintained by the insulation of the chamber.

The closing of the contact is obtained by any means.

Resistors operating at the instant of closing or opening, and insertedby any method, as well as capacitors insuring the distribution of thevoltage between chambers connected up in series, may be connected up inparallel with the cut-out contacts or outside the chamher.

In the variant in FIG. 2, the end contact 9 between the moving contact10 and the semi-moving contact 11 in FIG. I is replaced by a contact 9between the moving contact 10 and fixed contact fingers 2I. fluid-tightsealing being, as previously, insured by the valve 5 placed between thefixed part 6 and the moving part 7.

FIG. 3 is a variant of FIG. 1, in which the respective dimensions of theparts have been modified.

In FIG. 4, the device comprises two moving contacts 22 and 23 forming anend contact 9 and comprising, respectively. exhaust orifices 24 and 25in the low pressure tanks 2 and 3. Fluid-tight scaling is effected. aspreviously, by the valve 5. At the beginning of the operation, themoving contact 23 is pulled by the insulating rod 15, and after theopening of the valve 5, the two contacts 22 and 23 are pneumaticallyaccelerated by the high-pressure of the tank 1.

In FIG. 5, the sliding seal 4 in FIGS. 1 to 4 is replaced by a seatcomprising a seal 26.

When the cut-out currents are lower, the double blowing means may bereplaced by a single blowing means, as shown by FIG. 6. Inside thehigh-pressure tank 1, an end contact 9 is produced between the movingpart 10 and the semi-moving contact 11 pushed by the spring 12. At thebeginning of the opening, the insulating rod 15 exerts a traction efforton the moving part 10, opens the valve 5 and the high-pressure actionpneumatically accelerates the moving part 10. The releasing of thecompressed air of the tank 1 towards the single low-pressure tank 2,passing through the tube I0 and the orifices 17, causes theextinguishing of the arc.

The device has been shown in FIG. 6 with end contacts 9 and a slidingfluid-tight sealing means 4, but it may be provided with thearrangements shown in FIGS. 2 and 5.

The device which is the object of the invention is suit able for anyvoltages as a circuit-breaker and enables a very fast cancelling ofdefects. It may also be used in the synthetic test circuits for circuitbreakers. In that case, that device insulates the high-voltage circuits,cutting off the discharge of the main capacitor battery in the case offurther priming of the capacitor being tested at the passing throughzero of the current. It then makes it possible to effect a furthercut-out attempt on the following passing of the current through zero.

The high are voltages produced by that device may also be used invarious directcurrent circuit cuttingout or switching configurations.

What is claimed is:

1. In a pneumatic switch comprising a cut-out chamber containing acompressed gas and, in that chamber, a set of contacts whose movingcontact is installed on a moving rod crossing through a wall of saidchamber, the improvement wherein: said moving rod is hollow at leastthroughout the whole of its length entering said chamber, the inside ofsaid rod communicating, through an opening placed in the portion of therod outside said chamber, with a low-pressure medium, the body of avalve being installed round the moving 5 contact which, when the switchis in the closed position, is closed and separates the inside of thesaid rod from the compressed gas contained in the said chamber,electrodynamic means being placed on the outstide of said chamber injuxtaposition to said rod and IQ acting directly thereon to cause, whenthey receive, a current emission, the initiation of movement of saidmoving rod, and subsequently, the opening of said valve, this causingthe accelerated continuance of the opening movement of said moving rodunder the action 15 of the compressed gas contained in said chamber,said chamber including a hollow body, defining said seat, said fixedcontact being fitted within an opening within said seat with said seatopening leading outside said chamber, to a low-pressure medium, saidcut-out chamber consisting of a first cylinder, said hollow bodyconsisting of a second cylinder having the same axis and being ofsmaller diameter, said second chamber leading at said first end intosaid chamber, and a cylindrical tank which communicates with the outsideatmosphere through an orifice having a small cross section and intowhich the second end of said second cylinder leads and being arranged atthe end of said first cylinder, on the output side of said hollow body.

2. In a pneumatic switch comprising a cut-out chamher containing acompressed gas and, in that chamber, a set of contacts whose movingcontact is installed on a moving rod crossing through a wall of saidchamber, the improvement wherein: said moving rod is hollow at leastthroughout the whole of its length entering said chamber, the inside ofsaid rod communicating, through an opening placed in the portion of therod outside said chamber, with a low-pressure medium, the body of avalve being installed round the moving contact which, when the switch isin the closed position, is closed and separates the inside of the saidrod from the compressed gas contained in the said chamber,electrodynamic means being placed on the outside of said chamber injuxtaposition to said rod and acting directly thereon to cause, whenthey receive, a current emission, the initiation of movement of saidmoving rod, and subsequently, the opening of said valve, this causingthe accelerated continuance of the opening movement of said moving rodunder the action of the compressed gas contained in said chamber, saidcut-out chamber comprising a cylinder, the moving rod extending throughthe wall of said chamber on the axis thereof, a cylindrical tankcommunicating with the outside atmosphere through an orifice of smallcross sec tion, and said opening within said rod outside said chamberopening up into said cylindrical tank, on the output side of the movingrod.

1. In a pneumatic switch comprising a cut-out chamber containing acompressed gas and, in that chamber, a set of contacts whose movingcontact is installed on a moving rod crossing through a wall of saidchamber, the improvement wherein: said moving rod is hollow at leastthroughout the whole of its length entering said chamber, the inside ofsaid rod communicating, through an opening placed in the portion of therod outside said chamber, with a low-pressure medium, the body of avalve being installed round the moving contact which, when the switch isin the closed position, is closed and separates the inside of the saidrod from the compressed gas contained in the said chamber,electrodynamic means being placed on the outstide of said chamber injuxtaposition to said rod and acting directly thereon to cause, whenthey receive, a current emission, the initiation of movement of saidmoving rod, and subsequently, the opening of said valve, this causingthe accelerated continuance of the opening movement of said moving rodunder the action of the compressed gas contained in said chamber, saidchamber including a hollow body, defining said seat, said fixed contactbeing fitted within an opening within said seat with said seat openingleading outside said chamber, to a low-pressure medium, said cut-outchamber consisting of a first cylinder, said hollow body consisting of asecond cylinder having the same axis and being of smaller diameter, saidsecond chamber leading at said first end into said chamber, and acylindrical tank which communicates with the outside atmosphere throughan orifice having a small cross section and into which the second end ofsaid second cylinder leads and being arranged at the end of said firstcylinder, on the output side of said hollow body.
 2. In a pneumaticswitch comprising a cut-out chamber containing a compressed gas and, inthat chamber, a set of contacts whose moving contact is installed on amoving rod crossing through a wall of said chamber, the improvementwherein: said moving rod is hollow at least throughout the whole of itslength entering said chamber, the inside of said rod communicating,through an opening placed in the portion of the rod outside saidchamber, with a low-pressure medium, the body of a valve being installedround the moving contact which, when the swiTch is in the closedposition, is closed and separates the inside of the said rod from thecompressed gas contained in the said chamber, electrodynamic means beingplaced on the outside of said chamber in juxtaposition to said rod andacting directly thereon to cause, when they receive, a current emission,the initiation of movement of said moving rod, and subsequently, theopening of said valve, this causing the accelerated continuance of theopening movement of said moving rod under the action of the compressedgas contained in said chamber, said cut-out chamber comprising acylinder, the moving rod extending through the wall of said chamber onthe axis thereof, a cylindrical tank communicating with the outsideatmosphere through an orifice of small cross section, and said openingwithin said rod outside said chamber opening up into said cylindricaltank, on the output side of the moving rod.